Silicon has been a sought after anode material for years due to its high capacity 3800 mAh/g in comparison to battery grade graphite 350 mAh/g. Silicon however does not cycle reversible due to the very significant volume expansion associated with intercalation and the lack of a stable solid electrolyte interface (SEI) layer.
Lignin is a waste product of the pulp-and-paper industry produced at a rate of millions of tons per year and is burned for calorific value. It is the principal noncarbohydrate constituent of wood that provides rigidity to the cell walls of plants. A sustainable, renewable resource, lignin is derived from woody plants such as trees and switchgrass.